Pressure-gage.



'H. P. KRAFT & M/G. SCHWEINERT.

Patented Apr. 3,1917.

INVENTORS 21 1 I g; Bilflomeys,

my E S S E N W W UNITED STATES PATENT OFFICE.

HENRY P. KRAFT, OF RIDGEWOOD, AND MAXIMILIAN CHARLES SGHWEINERT, 0]! "WEST HOIBOKEN, NEW JERSEY.

IPIRESSURE-GAGE Specification of Letters Patent.

Patented Apr. 3, 191?.

Application filed August 10, 1910, Serial No. 576,580. Renewed June 27, 1916. Serial No. 1%,2264.

To all whom it may concern:

Be it known that We, HENRY P. KRAFT, residing in Ridgewood, in the countv of Bergen and State of New Jersey, and MAXI- MILIAN CHARLES Sonwnmnnr, residing in lVest Hoboken, in the county of Hudson and State of New Jersey, both citizens of the United States, have invented certain new and useful Improvements in Pressure-Gages, of which the following is a specification.

This invention relates to pressure gages, and aims to provide certain improvements therein.

The object of the present invention is to provide a small and fiflll'lpitct pressure gage or indicator for pneui'natic tires or the like which is of cheap and simple construction. Various gages have heretofore been pro posedbut these have conunonly involved the use of a piston 01- similar member designed to be moved against the tension of a spring by the pressure of the air. It is diflicult in this type of gage to pack the piston sufficiently to prevent leakage while avoiding any friction which would disturb the precision of its indications. Our present invention 15 designed to provlde a gage 111 -which the use of a piston is avoided and .WlllClllS extremely simple and cheap in its construction, and not likely to become 1noperative in use. According to our invention We employ an indicz-tting member a tube of metal or other suitable substance which is normally curved, and which straighten out when air under pressure is admitted within it. Such tubeis preferably not bent to spiral form but is given only a slight curvature corresponding preferabl to about a quarter of a circle. The end of the tube constantly has an arc of movement, the center of which more or less approximates in position the lined end of a tube. Means are provided for registering the vary-- ing degrees of pressure so that when the gage removed from the tire valve for in stance its indications can be read even though the pressure within the tube is relieved. i

The invention involves certain other features of improvement which will be hercinafter pointed out.

Referring to the drawings which illustrate one form of the invention,'

on an enlarged scale.

tends to Figure 1 is a sectional view of the gage Fig. E2 is a view substantially at right angles to Fig. 1 showing the gage in section.

Fig. 3 is an elevation of the upper part of Fig. 2.

Referring to the drawings let A indicate a suitable casing of curved form having at its lower end a cap B which is designed to retain a packing disk C Within the end of the casing. Mounted in the. casing is a tube 1). the lower end of which passes through and is connected to a disk E with a leak-tight joint, the disk being held within the end of the casing in any suitable man nor. At its lower end the tube D is closed but it is provided with a lateral opening it so that when the gage is pressed down over a tire valve as shown in Fig. 1; the imperforate and of the tube will depress a defiatinggg' pin G- of the tire and air will pass through the opening, F into the interior of the tube. The packing G at this time forms a leaktight joint around the upper end of the valve shell so that the air cannot escape except into the tube 1). The tube is con structed of light metal or rubber or other suitable niaterial of which a tube can be formed which will have the necessarycapacity of straightening out under pressure, and of returning to its initial shape when the ]'n'essure is relieved. lhe tube is preferably flattened out.

At its upper end the casing is preferably enlarged. to accoi'nmodate a greater range of u'iovcrnent of the tube at this end. As the tube straightens out under pressure its end describes an arc the center of which is not far removed from the lower end of the tube. Any suitable means may be provided ill? lltl

for utilizing the movement of the tube and Illlll lllllllli stance, the indications may be read notwithv Standing that" the pressure within the tube is relieved. Various means may be pro vidcd for accomplishing this result, but we prefer the construction illustrated in Fig. 1 wherein a ratchet J is employed following in shape the arc of movement of the end of the tube D and provided with a series of teethwhich are designed to ,,,be-successiv ely engaged by the end of the tube. The casing A is preferably movably mounted so that it may be pressed outwardly against the ratchet bar J of the tube as the latter passes the high points of the teeth in the bar. In

' the construction shown the bar is pivoted at K and is provided with a thumbpiece or handle L which is rigidly fixed to the body of the bar. A spring M is preferably provided which presses against the'under side of the thumb piece and normally holds the bar J in its inward position. As the tube rides past the teeth, the bar moves outward slightly to engaging position. In some cases the bar may be fixed and the elasticity of the tube relied upon to permit its end to move past the teeth. We prefer the spring construction shown since it not only reduces the resistance to movements of the tube but also permits the easy restoration of the tube to its normal or initial position. This is done by pressing the thumb piece L mwardly after the pressure is relieved. By preference'the ratchet bar J is formed as a cover for the casing A or asa partof the cover.

In some cases it may be necessary or desirable to reinforce the action of the tube -D eitherto cause it to have suflicient resistance to the pressure or to restore it to its normal condition. after the pressure is removed. In such cases a spring may be employed arranged in such manner as to resist the straightening of the tube. A simple arrangement is shown in Fig. 1 wherein the spring constructed as a leaf spring having its lower end attached to the casing and its upper end bearing against the tube D near the free end of the latter.

The gage thus provided is extremely cheap and simple to manufacture. It is of convenient shape to be carried in the pocket r and has no parts which are liable to get out complication.

of order. Theuse of a piston is avoided and the whole construction is free from past which said tube moves, said'part and tube constituting a scale and indicating member, and-means for holding said tube in its varying positions. 2. A pressure gage having a pressure member comprising a tube curved through an arc of approximately 90, and adapted to straighten under pressure, means for indicating the pressures including said tube or a part of the indicating means, and means:

for holding said tube in its varying positions. v

3. A pressure gage having v a pressure member comprising a curved tube, one end of which is adapted to be connected with a.

source of pressure, and the other end of which is adapted to move as the tube straightens under pressure, and a fixed part past which said tube moves, said part and tube constituting a scale and indicating member, and means for holding said tube in .its varying positions, said means comprising a ratchet bar.

4. A pressure gage having a pressure member comprising a curved tube, one end.

of which is adapted to be connected with a source of pressure, and'the' other end of which is adapted to move as the tube straightens under pressure, and a fixed part past which said tube moves, said part and tube constituting a scale and indicatingmember, and means for holding said tube in its varying positions, said means comprising a curved ratchet bar. I

5. A pressure gage having a pressure member comprising a curved tube, one end of which is adapted to be connected with a source of pressure, and the other endof which is adapted to move as the tube straightens under pressure, and a fixed part past which said tube moves, said part and tube constituting a scale and indicating member, means for holding said tube in its varying positions, said means comprisin a ratchet bar, and means for yieldingly ho ding said ratchet bar in position.

"6. A pressure gage having a pressure member comprising a curved tube, one end of which is adapted to be connected with a source of pressure, and the other end of which is adapted to move as the tube straightens under pressure, and a fixed part past which said tube moves, said part and .tube constituting a scale and indicating member, and means for holding said tube. in

its varying positions, said means comprising a pivoted spring-mounted ratchet bar adapted to be moved by hand from its en- "I gag ng to its disengaging position.

4 7. A pressure gage, having a pressure I member comprising a curved tube, one end of which is adapted to be connected with a source of pressure, and the other end of which is adapted to move as the tube straightens underpressure, and a fixed part past which said tube moves, said art and tube constituting a scale and indicatlng memher, and means for holding said tube in its \arying positions, said means comprising a spring-mounted ratchet bar curved to correspon'i'i to the path of movement ofthc end of said tube, and adapted to'e'ngzrge said end.

8. A pressure gage having a pressure member romprising a curved tubc,.one end 'of which is adapted to be connected with a source of pressure, and the other end of which is adapted to move as the tube straightcns under pressure, and a fixed part past which said tube moves, said part and tube constituting a scale and indicating member, means for holding said tube in its mrying positions, said means comprising a springanounted ratchet bar curved to correspond to the path ofmovement of the end of said tube and adapted to engage saidend, and a handle for releasing said bar.

S). A pressure gage comprising a casing having a part adapted to fit the end of a tire valve, a tube in said casing having its lower end in connection with said part, and said tube being curved to materially less than a semi-circle, a scale on sald caslng past pressure, means for detachably connectin said gage with the valve of a. pneumat tire for admitting. air to said tube, an

means for depressing the deflating-pin the tire valve, said means constituting an e: tension of said pressure tube.

In witness whereof, we have hereun: signed our names in the presence of two suE scribing witnesses.

HENRY P. KRAFT. MAXIMILIAN CHARLES SOHWEINERT. Witnesses:

'1. F. WALLACE, FRED WRIT i l l I It is hereby ci artified that in Letters Patent No. 1,221,548, granted April 3, 1917 upon the application of Henry P. Kraft, of RidgtBWOOll, and Maximilian Chmib Schw0incrt, ufWestHohdkiihNewJersey, for an improvement in' Pressure-Gngvs,'

an nrror appvnrs in the printbclspvcificntion rsquiring correction as follows: Page.

line 72. claim 2, furthe word 01' read ax: and thht'thn said l..etturs Patent shnul be rmul with this corrvction therein that the suiun'nmy cmiform tn lhc rc-cnrd l thv ('u in thv Patent Office.

Signed and sealed this 30th day of April, A. D., 1918.

{5min} F. W. [1. CLAY. 

